US1418991A - Screw propeller - Google Patents

Description

G; H.- THOMPSON AND J. CURRIE. SCREW: PROPELLER.

APPLICATION HLED nEc.2a. 92o.

Patented June 6,1922.

ATTORNEY PATENT. omen.

GEORGE E. THOMPSON AND JOHN CURRIE, or SEATTLE, wAsHm K SCREW PROPELLE Specification of Letters Patent. Patent d J 19 Application filed December 28, 1920. Serial No. 433,572.

To all whom it may concern:

Be it known that we, GEORGE H. THOMP- SON, a subject of the King of England and JOHN CURRIE, a citizen'of the United States,

residing at Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Screw Propellers, of which the following is a specification.

This invention for marine vessels.

The object of our invention is, generally,

to provide a device of this character'whereby power may be utilized more fully than hitherto for driving a vessel.

A specific object of the invention is to provide a propeller having blades of large areas arranged to produce a minimum of drag and which operate with an absence of churning. p

The invention consists of a propeller having a plurality of bifurcated blades of peculiar form which are disposed in spiral or helical relations. I

The invention further consists in the novel construction, adaptation and combination of parts as will be hereinafter described and claimed.

In the accompanying drawings, Figure 1 is an end elevation of a propeller embodying our invention. Fig. 2 is a side elevation of the same, and showing the relative arrangement of the blades. Figs. 3. 4, and

' 5 are sectional views through 3--3, 4-4,

and 5-5 of Fig. 1.

In said drawings, the numeral 10 designates thepropeller hub provided with a plu-.

rality of bifurcated blades, denoted by A, B, C, which are disposed spirally about the hub for revolutions in different planes.

Each of said blades comprises a shank ele-' ment 11 and two fluke elements 12 and 13.

Said shank and flukes are formed to be approximately helical in sections taken concentric of the propeller axis. As shown in Fig. 4, the flukes are of substantially planoconvex forms in tranverse sections, the convex face being forward in the leading fluke and to the rear in the. following fluke of a blade. The leading fluke 12 is curved forwardly from the shank to the tip thereof and the other fluke 13 is curved rearwardly as best represented in Fig. 3, while the outer relates to screw propellers.

with respect to the e whereby the water may travel in an unbroken state from in front of the leading fluke 12 to the rear of the following fluke '13.

Similar to the flukes, the blades themselves are-disposed in such relations with respect to each other to provide therebetween passages circumferentially of the propeller.

By forming both the blades and the flukes thereof in helical relations they offer little resistance when revolving through the water but provide a maximum driving force to propel a vessel.

The curving of the blades in the respective flukes from the region of their divergence to the fluke tips serves to reduce the centrifugal movement of the water without breaking the same.

By arranging the blades and their flukes tions with respect to each other about the hub, the bifurcation or fluke elements of said blades being broad and of substantially plano-convex form in transverse section with the convex sides of the complementary flukes at the'front-and rear sides respectively, the the complementary flukes of a blade being .curved to have the tipsv and outer side portions thereof respectively directed forwardly and rearwardly or toward each other and with 'the outer edges of each pair of flukes coextensive and in the similitude' of an elongated letter S. Signed at Seattle, Washington, this 13t day of'December 1920. H

GEORGE H. THOMPSON.

JOHN CURRIE. Witnesses: PIERRE BARNES, MARGARET G. SUPPLE.

of bifurcated blades disposed in helical rela-

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